I think forever and beyond! We have had a container in our frige for well over a year, and it is the same as the day we opened it. Perhaps someone else will offer different info...but we continue to enjoy it.

Over the last ten years, I've found dark miso paste on perhaps 3 occasions. My last package was purchased in June 2005. It will hopefully last for several years. I despair of finding another package of dark miso, and have carefully packaged it in plastic wrap and an airtight plastic container. It doesn't ever get old; unfortunately we use it up eventually. Enjoy!

Really? I can imagine having trouble a range of miso in many you live that you have so much trouble finding it? If nothing else, you can mailorder it by the ton from any of the many Japanese and Korean groceries in LA and I assume SF too. In NYC, it's even starting to show up in grungy neighborhood supermarkets!

Actually, I have had miso go bad. I use lots of miso and have containers of light,med , dark, and different grains in my fridge all the time. I think at some point I became bored with the white mild miso, and the container of white got pushed to the back and not used for a LONG time, 2-3 years?Not that I don't clean out my fridge every couple months, but it being miso, that lasts forever, it would always go back to the back of the fridge.Well I pulled it out to make a light dressing for someone who is not a very adventurous eater. I opened it up and it had mold, some of which was bright orange. Somewhere I have heard, that amongst mold, the bright orange is one you don't want to mess with, certainly not feed to a friend that doesnt like to experiment with exotic foods!!!!So, a some point, at least the mild white miso, can be past it's prime